This invention relates to overhead doors, particularly the roll-up or upwardly-acting type which are used in truck trailers.
Overhead doors are commonly used as garage doors, at vehicle docking entrances and on cargo-carrying vehicles such as trucks, semi-trailers, and the like. Typically these doors are moved along an L-shaped track from a vertical door-closed position to an overhead horizontal door-open or storage position. In some situations these doors are one piece and thus swing as one piece from the closed position to the open position and back. However, doors which are constructed from a plurality of laterally-extending hinged sections have become popular. These doors usually include a biased spring-type operator which assists in the manual opening and closing of the door.
In the sectional doors, hinges join the sections to each other and roller assemblies, which are part of the hinge assembly, guide the door sections along the track as the door is moved between the closed and open positions. These hinge and roller assemblies protrude from the door surface.
Overhead Door Corporation of Dallas, Tex., U.S.A. and Whiting Roll-Up Door Mfg. Corp. of Akron, N.Y., U.S.A. are major manufacturers of such doors and each has patented various door constructions. Typical sectional doors, hinges and roller constructions are shown in patents such as U.S. Pat. Nos. 4,306,756; 4,205,713; 3,693,693; 3,227,205; 3,213,924;, 2,902,087; and 2,869,637.
In such door systems, it is occasionally necessary to remove a section, a hinge or a roller for repair or replacement. In existing doors the hinges are riveted to the sections, thus making it difficult to remove sections or hinges for replacement or repair. Removing riveted parts can be destructive, time-consuming and expensive. This is particularly a problem in the trucking and transportation industry where the entire vehicle is out of service while a door is being serviced.
It is therefore the primary object of this invention to provide a sectionalized, upwardly-acting door assembly in which the door sections, hinges and rollers can be efficiently removed, repaired or replaced without the removal of mechanical fasteners.
Furthermore, the fact that the hinges extend into the cargo area has resulted in the hinges catching or snagging on cartons and goods. Such snagging has resulted in damaged goods as well as jammed and/or damaged doors.
It is another object of this invention to provide a system in which the door, hinge or roller does not catch or snag on shipped goods.
Typically sectionalized overhead doors are made of wood, plastic-coated wood, aluminum-clad wood or metal sections, principally for strength and durability. However, in the trucking and transportation industry, such doors add weight to the vehicle decreasing fuel efficiency, as well as reducing regulation-defined cargo carrying capacity. Such doors are also heavy and thus difficult to service. As a result there has been a trend toward using lightweight hollow-core or foam-filled door sections.
It is therefore another object of this invention to provide a hinge construction which is suitable for use with lightweight door constructions.
These and other objects of this invention will become apparent from the following description and appended claims.